DNV GL Report: How reliable are PV modules

Thu, 01/06/2017 - 13:31

DNV GL released the third edition of the DNV GL PV Module Reliability Scorecard analysing reliability test results of more than 50 commercially-available PV module models.

Logo: DNV GL


Frederic Dross, Head of Module Business
Mobile: +1 (650) 307-0703

Although the dramatic module price drop of recent years has helped to accelerate PV industry growth, concerns over cost reduction at the expense of module quality have persisted. As project financiers rely on performance prediction over several decades, it is important to understand the long-term performance of PV modules. The DNV GL Product Qualification Program (PQP) submits PV components to a unique set of tests which gives the clarity needed by module manufacturers, developers and financiers.

This program serves about 70 % of the largest PV manufacturers and a network of more than 175 developers, EPCs, banks and financiers, representing a PV-component buying power estimated to be more than 30 GW per year. DNV GL runs its Product Qualification Program for PV modules, PV inverters and energy storage systems.

Manufacturers submit their components to a unique set of tests defined by taking into account the latest advancements in component reliability science and the lab testing requests from the downstream community. This study covers five major reliability tests: thermal cycling, dynamic mechanical load, damp heat, humidity freeze and potential induced degradation. Participation in the Scorecard is an integral part of the DNV GL Product Qualification Program. As a consequence, all modules tested underwent the exact same selection process and testing scope.

Top findings in the 2017 Scorecard include:

1. Most modules tested maintain performance after reliability testing. However, the bottom quartile of most tests exhibit degradation levels that could put systems at financial risk.

2. Specific Bill of Materials (BOMs), factories, and manufacturer do matter: the same module type with different BOMs or manufacturing location often perform quite differently.

3. The size of the manufacturer is not a good indicator of performance in reliability testing. The same manufacturer may produce modules with a large spread in performance in reliability testing.

4. The number of participants in the DNV GL Product Qualification Program and therefore in the Scorecard have been steadily growing. In this edition of the Scorecard, the number of manufacturer participants jumped by 69% compared to last year.

Cover: PV Module Reliability Scorecard 2017
The 2017 PV Module Reliability Scorecard is available for free download via the DNV GL website.

All participating manufacturers receive a detailed report about the performance of their components in the tests. Over 3,000 industry stakeholders downloaded last year’s report. Since this is the third instalment of the PV Module Reliability Scorecard, it can now additionally be identified which manufacturers have maintained top performance positions consistently and which are the most improved since 2014. Many additional manufacturers appeared in this year’s edition for the first time.

“Our Product Qualification Program and Scorecard help create clarity for players in the solar market,” said Ditlev Engel, CEO DNV GL – Energy. “Testing helps manufacturers deliver better quality modules and supports financiers and developers in taking informed component purchasing decisions. We are committed to support the growth of the solar industry and to contribute to a global sustainable energy future.”

“While a 25-year performance warranty is standard in the industry, most PV module models, with a specific Bill of Materials, have actually been in use for less than a few years, so there is a limited amount of data on how equipment holds up over time,” said DNV GL’s Jenya Meydbray, Vice President, Strategy & Business Development, Laboratory Services, and the study’s lead author. “Though there is no truer test of a module’s reliability and long term performance than decades of real-world field experience, since 2012, the DNV GL Product Qualification Program and the PV Module Reliability Scorecard’s findings have become a critical resource to an industry looking to better understand risk in a commercially reasonable timeframe.”

DNV GL intends to update the PV Module Reliability Scorecard on an annual basis, with the 2018 edition expected to be published in the first half of next year. Additional modules tested through the DNV GL Product Qualification Program will be featured. A similar report focused on PV inverters is planned for release in late 2017.